Think it would have benefited a Conservative Government (though maybe if Disraeli failed to pass the bill he might have resigned, given that a party revolt was what would have most likely derailed his bill) in the short-term, but agitation would probably have been too much and they would eventually have to concede to Reform, and lose to the Liberals in the subsequent election.
In 1870, with the completion of the passages of the 13th, 14th, and 15th (Reconstructionist) Amendments US Adult Male Negroes (including those among four million newly freed ex-slaves) had the full voting franchise, and Jim Crow was still years away from even beginning to be instituted.
In such a situation, it would have been unthinkable for the epicenter of the English Speaking Peoples to still have no voting franchise for English White Male textile workers in Manchester while Black Mississippi sharecroppers enjoyed the right to vote.
IMVHO, and I confess I'd respect a British opinion better than my own in this regard, the longer the Conservatives could hold on with the moth eaten franchise as it existed under the Great Reform Act of 1832 the stronger both the Liberals and eventually the Socialists will become, with working class radicalism growing all the time. ITTL, a Socialist government by WWI perhaps?
